Why You Shouldn’t Close Your Air Supply Vents

Indoor temperature control is something many Minnesota homeowners don’t give a second thought to — that is until the temperature is beyond the desired comfort level. Then, many people adjust the thermostat. But if the issue persists, it could be time to check the HVAC registers or air supply vents. Bloomington Heating & Air provides high-quality residential HVAC maintenance services to keep your system running efficiently year-round. Contact us today.

What Happens If I Close The Air Vents?

Through a combination of design and engineering, an HVAC unit and its connected ductwork collaborate to supply a specific amount of air to each room, based on the room’s square footage. This creates a tedious balance that can negatively affect the entire house by closing even one vent. As a result, four common impacts are:

Imbalanced Static Pressure

When the heating and cooling system runs, the produced airflow enters a room through supply registers and exits through return registers. Closing either point causes a discrepancy in the pressure gradient. If the supply point is inhibited, the return vent still continues to pull whatever air is in the room back to the unit, creating a depressurized room. Many homeowners are unaware these situations affect the home’s indoor air quality (IAQ). As the room loses pressure, unfiltered air enters through small cracks and gaps in the structure. Since this is often outside air, allergens, dust, and other microscopic pollutants bypass the HVAC filter and diminish the IAQ.

No Energy Savings

An HVAC system produces a fixed amount of climate-controlled air based on the set indoor temperature. The system has no idea if you’ve left every vent in the home wide open or selectively closed four to guide the air elsewhere. In turn, closing vents produces no energy savings and increases utility costs.

Extra Wear & Tear On The HVAC Unit

Think of a home as a system of drinking straws. What happens if you draw liquid into the straw then cap one end with a finger? The liquid can’t flow out and you’re left with a finger indentation from the pressure build-up. Essentially the same thing happens when you close air vents in unused rooms, but the finger indentation, in this case, is extra wear and tear on the HVAC unit. When airflow is encumbered, the static pressure inside the ductwork system increases, along with the strain on the blower fan. This can lead to a number of common AC issues or even system failure.

Erratic Comfort

Although it may seem like an exercise in futility by adjusting individual supply registers, it’s essential for achieving an adequate airflow volume regardless of a room’s location. If even one HVAC vent is closed, it disrupts the flow and affects temperature consistency. A common example is too much airflow in one room while another receives a scant amount.

Schedule Residential HVAC Maintenance

If you or someone else has closed supply vents, don’t worry! Open and adjust them — the vast majority of the time a closed vent or two won’t cause the HVAC system to go haywire. But, if you notice the fan isn’t as effective, then give Bloomington Heating & Air a call to schedule a system check-up. We’ll gladly inspect the unit and measure static pressure to determine the health of the system.